JP4280578B2 - Intake air intake system for internal combustion engine - Google Patents

Description

  The present invention relates to an intake air introduction apparatus including a surge tank having an inlet for introducing blow-by gas and a plurality of branch pipes branched from the surge tank and connected to respective cylinders of an internal combustion engine.

2. Description of the Related Art Conventionally, an internal combustion engine equipped with a so-called blow-by gas processing device that treats gas (blow-by gas) leaked from a combustion chamber of an internal combustion engine into a crankcase by introducing it into a surge tank and combusting the gas is disclosed. Are known. According to such a blow-by gas processing device, highly corrosive blow-by gas is quickly discharged from the crankcase, so that corrosion of metal parts in the case can be suppressed as much as possible (for example, (See Patent Document 1)
JP-A-8-210118

  By the way, when the throttle valve built in the throttle body of the internal combustion engine is throttled, a negative pressure is generated downstream of the throttle valve. The blow-by gas introduced into the surge tank may flow backward to the throttle body due to the negative pressure. When such a backflow occurs, the oil component contained in the blow-by gas may adhere to the valve and adversely affect its opening / closing operation.

  It is an object of the present invention to provide an intake air introduction device for an internal combustion engine that can suitably suppress such a backflow of blow-by gas toward the throttle body.

The invention described in claim 1 is an intake air introduction apparatus comprising a surge tank having an inlet for introducing blow-by gas, and a plurality of branch pipes branched from the surge tank and connected to each cylinder of the internal combustion engine. A collision portion where blow-by gas introduced from the introduction port collides is formed inside the surge tank between the introduction port and a throttle body connecting portion of the surge tank, and each branch pipe is formed in the surge tank. An inner wall of a fastening portion for integrally forming the surge tank along the outer periphery thereof, wherein the collision portion is recessed in a part of the surge tank to fasten the surge tank to the internal combustion engine. It is characterized by being.

  According to the said structure, when blow-by gas flows in into a surge tank from an inlet, the diffusion of blow-by gas in a surge tank is accelerated | stimulated because the gas collides with a collision part. As a result, blow-by gas flowing in from the introduction port is uniformly distributed by each cylinder, and at the same time, it can be prevented from flowing back to the throttle body side.

Further, when the surge tank is fastened to the internal combustion engine, a space for inserting a bolt, a tool for fastening the bolt, and the like is necessary. According to the configuration of claim 1 , a part of the surge tank is used. The space is secured by a fastening portion recessed in the interior of the housing, while the collision portion is configured by the inner wall. For this reason, compared with the structure where the said collision part is provided separately, spreading | diffusion of blow-by gas can be accelerated | stimulated, avoiding complication of a structure as much as possible.

According to a second aspect of the present invention, in the intake system for an internal combustion engine according to the first aspect , the fastening portion is disposed between adjacent branch pipes.
According to the above configuration, the opening of the branch pipe and each port of the internal combustion engine can be more reliably connected.

According to a third aspect of the present invention, in the intake air introducing device for an internal combustion engine according to the first or second aspect , the surge tank and the branch pipe are made of a resin material.
According to the said structure, the apparatus of Claim 1 or 2 can be easily formed in a desired shape now by resin molding.

In addition, since the rigidity of the resin material is low compared to the case of using a metal material or the like, the connectivity between the opening of the branch pipe and each port of the internal combustion engine is impaired due to vibration of the internal combustion engine or the like. There are concerns. In this case as well, such inconvenience can be avoided by adopting the configuration of claim 2 .

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment in which an intake air introduction device for an internal combustion engine according to the invention is embodied will be described with reference to the drawings.
FIG. 1 shows a front structure of an intake air introduction device, that is, an intake manifold 10 and a surge tank 11, and FIG. 2 shows a rear structure of the device. FIG. 3 shows an exploded perspective view of the apparatus.

  As shown in these drawings, the intake manifold 10 and the surge tank 11 are composed of an upper divided body 12 and a lower divided body 13 which are divided into upper and lower parts, and these divided bodies 12 and 13 are joined and integrated with each other. It has a structure.

  As shown in FIG. 1, the upper divided body 12 is provided with a connection portion (throttle body connection portion) 16 to the throttle body 14 at the upper center. A throttle valve 15 is provided in the throttle body 14. Two branch pipes 10a, 10b, 10c, and 10d constituting the intake manifold 10 are provided on the left and right sides of the connection portion 16, respectively. These branch pipes 10 a to 10 d are integrally formed with the surge tank 11 along the outer periphery of the surge tank 11.

  Further, the portions between the two branch pipes 10 a, 10 b, 10 c, and 10 d provided on the left and right sides of the surge tank 11 are recessed in the surge tank 11. This recessed portion is a fastening portion 40 for fastening the surge tank 11 to the internal combustion engine. Specifically, a bolt hole 17 for fastening the surge tank 11 to the internal combustion engine is formed in the fastening portion 40, and the surge tank 11 is fastened and fixed to the internal combustion engine by a bolt inserted into the bolt hole 17. Is done. In addition, the insertion space 18 of the tool required in order to fasten a volt | bolt (not shown) by the fastening part 40 which makes a concave shape is ensured. Note that, according to the present embodiment, since the intake air intake device made of a resin material has low rigidity, for example, the connection between the openings of the branch pipes 10a to 10d and the respective ports of the internal combustion engine due to vibrations of the internal combustion engine or the like. There is a concern about the loss of sex. For this reason, in the present embodiment, the portions between the two branch pipes 10a, 10b, 10c, 10d respectively provided on the left and right sides of the surge tank 11 are fastened to the internal combustion engine.

  The surge tank 11 is provided with an introduction port 19 for introducing blow-by gas into the tank 11. Incidentally, the introduction port 19 is connected to the head cover of the internal combustion engine through the blow-by gas passage.

  As shown in FIG. 2, each branch pipe 10 a to 10 d is opened 20 in the upper divided body 12, and these are connected to the ports of the respective cylinders of the internal combustion engine. In FIG. 3, the upper divided body 12 is composed of two members 12A and 12B.

The intake air is introduced into the surge tank 11 from the connecting portion 16 through the throttle body 14. Thereafter, the intake air is introduced into each cylinder of the internal combustion engine through the branch pipes 10a to 10d.
Further, blow-by gas is introduced into the surge tank 11 from the inlet 19 shown in FIG. Specifically, this will be described with reference to FIG.

  FIG. 4 shows a cross-sectional structure along the line AA in FIG. As shown in the figure, the fastening portion 40 described above is located between the introduction port 19 and the connection portion 16, and the surface facing the introduction port 19 is perpendicular to the inflow direction of the blow-by gas. Surface 32 is formed. The blow-by gas introduced into the internal space of the surge tank 11 from the introduction port 19 collides with the vertical surface 32 of the fastening portion 40 as shown by the arrow in FIG. Therefore, this vertical surface 32 is a collision part.

  By this collision, the blow-by gas is diffused and the lubricating oil contained in the gas is also diffused. As a result, the blow-by gas flowing from the introduction port 19 can be prevented from flowing back to the throttle body 14 side. As a result, the amount of lubricating oil adhering to the throttle valve 15 is also reduced, and problems such as opening / closing operation of the valve 15 due to such adhesion can be suppressed.

  In particular, the fastening portion 40 has a vertical surface 32 that is substantially perpendicular to the direction of the flow of blow-by gas introduced from the introduction port 19 as in the above configuration, so that diffusion of blow-by gas and lubricating oil can be achieved. Can be improved.

  Furthermore, since the blow-by gas collides with the fastening portion 40 and is diffused as described above, the same gas can be supplied to the intake manifold 10 without variation in the flow rate ratio thereof.

  In addition, the fastening portion 40 is configured by projecting a part of the surge tank 11 toward the internal space side in order to secure the insertion space 18 of the tool necessary for fixing the bolt. The diffusion of blow-by gas can be promoted while avoiding the complication of the process as much as possible.

In addition, you may change the said embodiment as follows.
In the above configuration, the surge tank 11 is directly attached to the internal combustion engine. However, for example, the surge tank 11 may be attached indirectly via another intake pipe.

  A vertical surface 32 that is substantially perpendicular to the fastening portion 40 is formed in the direction of the flow of blow-by gas introduced from the inlet 19 into the surge tank 11. On the other hand, it is not necessarily limited to this.

The front view of an air intake introducing device. The rear view of the same apparatus. The exploded perspective view of the device. Sectional drawing along the AA line of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Intake manifold, 10a-10d ... Branch pipe, 11 ... Surge tank, 12 ... Upper division body, 13 ... Lower division body, 14 ... Throttle body, 15 ... Throttle valve, 16 ... Connection part, 20 ... Opening, 17 ... Bolt hole, 18 ... insertion space, 19 ... introduction port, 32 ... vertical surface, 40 ... fastening part.

Claims (3)

In an intake air introduction device comprising a surge tank having an inlet for introducing blow-by gas, and a plurality of branch pipes branched from the surge tank and connected to each cylinder of the internal combustion engine,
A collision part where blow-by gas introduced from the introduction port collides is formed inside the surge tank between the introduction port and the throttle body connecting part of the surge tank ,
Each branch pipe is integrally formed with the surge tank along the outer periphery of the surge tank,
An intake air introducing device for an internal combustion engine, wherein the collision portion is an inner wall of a fastening portion for recessing a part of the surge tank and fastening the surge tank to the internal combustion engine . The intake air introducing device for an internal combustion engine according to claim 1, wherein the fastening portion is disposed between adjacent branch pipes . The intake system for an internal combustion engine according to claim 1 or 2, wherein the surge tank and the branch pipe are made of a resin material .

Images